Torque-limiting driver with a self-locking adapter

Abstract

An internal adapter for use in torque-limiting handles for interchangeable orthopedic tools contains a slidable collar component, house component, retaining ring, spring, driver component, cover and cam which engages a torque-limiting mechanism. A plurality of securing ball mechanisms releasably secure an orthopedic tool in the adapter, while a configuration of chamfered surfaces centrally stabilize the tool. A plurality of guiding chamfers located in a driver component rotationally secures the orthopedic tool.

What is claimed is: 
     
       1. A torque-limiting tool handle for releasably engaging orthopedic tools comprised of:
 a tool handle and having an internal handle cavity; 
 a plurality of components adapted to fit within said internal handle cavity to releasably secure an orthopedic tool in a manner that is sufficiently stable for use during an orthopedic procedure, wherein said plurality of components include 
 a slidable collar component having an external collar base with an tubular sliding portion containing a plurality of securing ball detent apertures and a retaining ring groove, 
 said tubular sliding portion creating an internal tool receiving channel and insertable into an interior collar channel of a housing component, 
 said interior collar channel of said housing component having a tapered inner surface which covers said plurality of securing ball detent apertures, wherein said tapered inner surfaces creates a smaller interior collar channel diameter at the front of said interior collar channel and a larger interior collar channel diameter at the rear end of said interior collar channel, and a stop-ridge, wherein said slidable collar component is slidable within said interior collar channel and said plurality of securing ball detent apertures are aligned with said tapered surface, 
 a plurality of securing balls wherein each one of said plurality of securing balls engages one of said plurality of securing ball detent apertures to decrease the diameter of said internal tool receiving channel, 
 a retaining ring contained in said retaining ring groove, 
 a spring adapted to provide outward force on said slidable collar component so that said plurality of securing balls are aligned with said smaller interior collar channel diameter and said retaining ring engages stop-ridge to prevent outward movement of said slidable collar component, 
 a driver component having a plurality of guiding chamfers, and 
 a cover which engages said internal handle cavity, 
 wherein inward force applied to said slidable collar component aligns said plurality of securing balls with said larger interior collar channel diameter to increase the diameter of said tool receiving channel; and 
 a cam, wherein said cam is secured to said driver component. 
 
     
     
       2. The apparatus of  claim 1  which has four securing balls and four securing ball apertures. 
     
     
       3. The apparatus of  claim 1  wherein said guiding chamfers are double square. 
     
     
       4. The apparatus of  claim 1  wherein said driver component has at least one flattened exterior surface and said cam has at least one corresponding flattened internal surface to prevent rotational movement of said driver in said cam. 
     
     
       5. The apparatus of  claim 1  which further includes at least one bearing. 
     
     
       6. The apparatus of  claim 1  wherein said cover and said internal handle cavity contain corresponding threaded portions. 
     
     
       7. A torque-limiting handle for releasably securing an orthopedic tool comprised of:
 a tool handle and having an internal handle cavity; 
 a torque-limiting assembly housed within said internal handle cavity, said torque-limiting assembly including at least one roller; and 
 at least one internal adapter adapted to fit within said internal handle cavity and releasbly secure the shaft of an orthopedic tool comprised of 
 a slidable collar component with an internal tool receiving channel, 
 said collar component having a plurality of securing ball apertures and a retaining ring groove, 
 a house component with an interior collar channel having a tapered surface creating a smaller interior collar channel diameter at the front of said interior collar channel and a larger interior collar channel diameter at the rear end of said interior collar channel and a stop-ridge, wherein said slidable collar component is slidable within said interior collar channel and said plurality of securing ball apertures are aligned with said tapered surface, 
 a plurality of securing balls wherein each one of said plurality of securing balls engages one of said plurality of securing ball apertures to decrease the diameter of said internal tool receiving channel, a retaining ring contained in said retaining ring groove, 
 a spring adapted to provide outward force on said slidable collar component so that said plurality of securing balls are aligned with said smaller interior collar channel diameter and said retaining ring engages stop-ridge to prevent outward movement of said slidable collar component, 
 a driver component having a plurality of guiding chamfers each having a transition chamfer, wherein said driver component secures said spring against said slidable collar component, and a cover which engages said internal cavity, 
 wherein inward force applied to said slidable collar component aligns said plurality of securing balls with said larger interior collar channel diameter to increase the diameter of said tool receiving channel; 
 a cam, and at least one bearing, wherein said roller engages said cam. 
 
     
     
       8. The handle of  claim 7  wherein said cam has a plurality of inclined areas interposed between gradual sloped areas that culminate in elevated areas. 
     
     
       9. The handle of  claim 8  wherein said roller is freely rotatable against said cam. 
     
     
       10. The handle of  claim 7  wherein said securing ball apertures are symmetrically arranged. 
     
     
       11. The handle of  claim 7  wherein said guiding chamfers are double square. 
     
     
       12. The handle of  claim 7  wherein said driver component has at least one flattened exterior surface and said earn has at least one corresponding flattened internal surface to prevent rotational movement of said driver in said cam. 
     
     
       13. The handle of  claim 7  wherein said cover and said internal cavity contain corresponding threaded portions. 
     
     
       14. The handle of  claim 7  wherein said shaft has a groove and a plurality of flattened surfaces separated by rounded transitions having corresponding chamfers, wherein the distance from the center of said groove to the leading edge of said corresponding chamfers is equal to the distance from the center of one of said securing balls to the leading edge of one of said transitional chamfers. 
     
     
       15. A torque-limiting handle for a medical shaft comprised of:
 a handle having an internal handle cavity, wherein said internal handle cavity has a threaded portion; 
 a torque-limiting assembly housed within said internal handle cavity, said torque-limiting assembly including at least one roller; and 
 an internal adapter configured to receive an orthopedic tool having a shaft with a groove and a plurality of flattened surfaces having corresponding chamfers and separated by rounded transitions having corresponding chamfers, said internal adapter being configured to fit within said internal handle cavity and comprised of a slidable collar component with an internal tool receiving channel, said collar component having a plurality of symmetrically arranged securing ball apertures and a retaining ring groove, 
 a house component with an interior collar channel having a tapered surface creating a smaller interior collar channel diameter at the front of said interior collar channel and a larger interior collar channel diameter at the rear end of said interior collar channel and a stop-ridge, wherein said slidable collar component is slidable within said interior collar channel and said plurality of securing ball apertures are aligned with said tapered surface, 
 a plurality of securing balls wherein each one of said plurality of securing balls engages one of said plurality of securing ball apertures to decrease the diameter of said internal tool receiving channel, 
 a retaining ring contained in said retaining ring groove, 
 a spring adapted to provide outward force on said slidable collar component so that said plurality of securing balls are aligned with said smaller interior collar channel diameter and said retaining ring engages stop-ridge to prevent outward movement of said slidable collar component, 
 a driver component having a plurality of guiding chamfers corresponding to said flattened surfaces of said orthopedic tool and at least one flattened exterior surface, 
 wherein said guiding chamfers have transition chamfers, and 
 a handle-engaging cover having a threaded portion corresponding with said threaded portion of said internal cavity, 
 wherein inward force applied to said slidable collar component aligns said plurality of securing balls with said larger interior collar channel diameter to increase the diameter of said tool receiving channel; and 
 a cam having an interior channel with at least one flattened surface; wherein said roller engages said cam; 
 wherein said at least one flattened exterior surface of said driver and said at least one flattened surface of said cam interior channel correspond to prevent rotational movement of said driver in said cam; 
 wherein the distance from the center of said groove to the leading edge of said chamfers corresponding to said rounded transitions of said tool shaft is equal to the distance from the center of one of said securing balls to the leading edge of one of said transition chamfers of said driver component and 
 wherein said slidable collar component, said house component, said securing balls, said retaining ring, said spring, said driver component, said cover and said cam are housed within said housing. 
 
     
     
       16. The handle of  claim 15  wherein said cam has a plurality of inclined areas interposed between gradual sloped areas that culminate in elevated areas. 
     
     
       17. The handle of  claim 15  wherein said housing is T-shaped. 
     
     
       18. The handle of  claim 15  which further includes two bearings, wherein in one of said bearings is on either side of said cam. 
     
     
       19. The handle of  claim 15  wherein said bearings are ball bearings. 
     
     
       20. The handle of  claim 15  wherein said slidable collar component has an exterior collar base.